35mm film canister, metal tins. anything that keeps them sealed in a cool dark place. i just germinated seeds about a month ago that ive had for about 2 years in a metal tin
i put them in "dime baggies" which are labeled so i know what seeds are in each bag. then i put all the baggies in a metal tin. its round, about 3-4" accross maybe. then i just keep that in one of my drawers. ive always kept my seeds like that and like ive said, ive stored seeds for years that way with no problems.
Keep them in a cool, dry, dark place - they will remain viable for YEARS. Archaeologists found seeds (not MJ, LOL) in Egyptian tombs that were thousands of years old and still sprouted.